An Information Disclosure Statement is enclosed along with a full description of prior Australian and P.C.T. patent Applications by the Inventor of this present Invention
1. Field of the Invention
The present invention relates to an aircraft landing wheel rotating apparatus primarily designed to achieve controlled forward rotation of the main landing wheels of commercial, and cargo aircraft prior to touch down with the runway thereby reducing wear on tires reducing impact loadings on the landing wheel assembly, reducing the possibility of sudden tire blowout. Improving aircraft stability at touch down by reducing differential torque reaction due to the fact that not all wheels impact the runway together and potentially improving brake efficiency by providing the option of a degree of retardation assistance after touch down during the deceleration of the aircraft while braking.
2. Description of the Prior Art
Aircraft wheel rotation devices or pre-rotation devices are widely known in the prior art of up to 50 years or more in the past.
The extensive interest shown by inventors both past and present highlights the potential importance of a system which overcomes the short falls of the prior art.
Aircraft landing wheel rotation devices forming the majority of the prior art have been developed for the fulfillment of countless objectives and requirements.
By way of example an international search report conducted by I.P. Australia returned Category A, documents defining the general state of the art which were not considered to be of particular relevance. These being the foreign patent applications FR2704514 A1 (PORTE) 4 Nov. 1994, DE29900944UI (MERLAKU) 20 May 1999, GB2311264A (TOON. ET. AL.) 24 Sep. 1997 certified copies of which are enclosed as part of the Information Disclosure Statement along with relevant translations.
It should be noted that the present invention was previously lodged as an Australian Patent Application AU2004237817, 9 Dec. 2004, Improvements in Aircraft Landing Gear which claimed priority of a Provisional Specification Number 2003906883, 15 Dec. 2003 Improvements in Aircraft Landing Gear, The Australian Patent Application was published by I.P. Australia on 30 Jun. 2005 less than one year prior to which the same inventor lodged this U.S. patent application. As regards the U.S. application the dates of the Australian Patent Applications should be considered in the case of a first to invent ruling. A P.C.T. application describing this present invention was lodged by this inventor with I.P. Australia on the 24 Oct. 2005.
Copies of the P.C.T. and Australian Patent Applications are enclosed along with the P.C.T. International Search Report which cited AU 2004237817 A1 (SODERBERG) 30 Jun. 2005 as the only document cited which was of particular relevance to the novelty of the P.C.T. application highlighting the unique features of the present invention which is in no way influenced by the Publication by I.P. Australia 30 Jun. 2005 since the present invention has been lodged with the U.S.P.T.O. within the requisite 1 year period and no other discloser or issuance of patent or inventors certificates have been performed. Two of the International Search Report cited patent applications DE29900944U1 (MERLAKU) 1999 and GB2311264A (TOON. ET. AL) 1997 mention the use of small electric motors. GB 2311264A (TOON. ET. AL) shows a remote mounted proprietary type of electric motor driving the aircraft wheel through either a shaft drive or friction drive on the tire while DE 29900944 U1 (MERLAKU) simply makes mention of a small electric motor. Neither system was considered by the International Search Report as being considered of particular relevance and neither is likely to be feasible in the crowded landing wheel assembly of modern day commercial aircraft for which the present invention is designed. An inspection of FIG. 3 of the Drawings associated with the present invention shows a wheel and brake assembly typical of the main load bearing landing wheel assembly found on the present day commercial, cargo, and all heavy duty fixed wing aircraft. It is clearly seen that there is extremely little free space in any of the main landing wheel assembly, incorporating a brake stack within the wheel along with the brake actuating mechanism and wheel support structure leave little or no free space for mounting a small proprietary electric motor.
Also pertaining to the prior art are an array of U.S. patents.
U.S. Pat. No. 5,746,393 Gennaro discloses an Aircraft Wheel Rotating Apparatus.
U.S. Pat. No. 5,165,624 Lewis discloses an Apparatus for pre-rotating aircraft wheels employing forced air and a vacuum.
U.S. Pat. No. 4,491,288, Sinclair discloses and Aircraft landing wheel rotating means.
U.S. Pat. No. 5,104,063 Hartley discloses an Aircraft landing gear pre-rotating system.
The respective U.S. patents listed also list an array of similar U.S. patent applications all directly related to pre-rotation of aircraft landing wheels prior to touch down.
While the majority of these devices fulfill their respective objectives the previously mentioned patents differ considerably from the principles and mode of operation of the present invention.
Few if any of the inventions associated with the prior art address what is claimed to be a significant problem associated with pre-rotation of aircraft landing wheels, this being either increased landing distance or increased brake loadings due to the loss of an amount of retardation energy that would otherwise be applied to the aircraft as a result of the energy dissipated during tire skidding and momentum transferred to achieve wheel rotation upon touch down.
This is a valid argument against pre-rotation of aircraft wheels since every increment of stopping distance can be critical in an emergency situation.
The present invention addresses this problem by providing retardation assistance as required and will have the potential to input greater retardation assistance over the deceleration distance of the aircraft than would have been the lost deceleration energy associated with bringing the non rotating landing wheel up to speed.
In addition to providing the option of retardation assistance and thus overcoming a claimed major draw back associated with pre-rotation of aircraft landing wheels the present application deviates significantly from the prior art by providing a mechanism for pre-rotation which is contained within the basic structure of the landing wheel assembly thus allowing use with the crowded inner wheel situation associated with large commercial aircraft whereby the inner wheel region of the main landing wheels, with the exception of the nose wheel, is almost completely filled with brake stack, torque tube, and bearings, and blocked on the inner face of the wheel by the brake actuating mechanism and support structure, thus negating the practical use of many of the prior art inventions.
In addition to the previously mentioned disadvantages of the prior art it can also be seen that many of these lack the start up torque and ease of rotational speed control necessary in the situation of normal wear and tear whereby binding and friction drag of some components of the aircraft wheel assembly is inevitable and can vary from one wheel to another and can easily be overcome by the mode of operation of the present invention which allows high start up torque and ease of rotational speed modulation under conditions of variable drag and frictional forces opposing the rotation.
The International Search Report conducted by I.P. Australia a copy of which is enclosed, cited what are considered to be the most relevant patent applications which most closely represent the general state of the art however these documents by PORTE, MERLAKU, TOON. ET. AL which were previously listed are classified as prior art references Category A, defining the general state of the art which were not considered to be of particular relevance.
The International Search Report cited only one document designated Category X, a document of particular relevance which is in fact this inventors own Australian Patent Application AU 2004237817A1 (SODERBERG) 30 Jun. 2005, which forms the basis of this present invention thus further high-lighting the significant difference between the present invention and all prior art,